Quick background - Apple again will have at least 2 versions of the iPhone X - one with a Qualcomm modem for CDMA networks (Verizon/Sprint) and one with an Intel modem for GSM networks (AT&T/T-Mobile). There is some evidence, most anecdotal, that the superior Qualcomm chip outperforms the Intel chip in terms of service connectivity (more bars), upload/download speeds (on LTE), and battery life (due to size of the components). Apple has admitted to throttling the Qualcomm chip to perform at the lower level of the Intel chip. It is clear that the Qualcomm variant comes with the premium parts. It also works on both CDMA and GSM networks, so it would work on AT&T for instance, and some data suggests that the Qualcomm variant pulls better data speeds on AT&T than the Intel version. Ok - so how do AT&T customers get the Qualcomm phone. Unfortunately, AT&T customers who purchase phones directly from Apple or AT&T, even if paid in full, will get the Intel version. However, if you purchase the phone from a US retailer like Best Buy, Target, or Walmart, you will get the Qualcomm version because these retailers carry the "universal" model of the iPhone which has the flexibility to work with all US carriers. Best buy is offering pre-sales but it is less clear whether Target and Walmart will have them and when. Now comes my question to someone who has insight into how these phones are locked to the carrier upon activation. My understanding is that if you activate the phone with a Verizon SIM card, regardless of what carrier you actually use, the phone will be unlocked as that is Verizon's iPhone locking policy. Verizon iPhones are factory unlocked. The question - does this have to be a Paid-In-Full phone or can you do the same with a phone purchased on a carriers installment plan? For instance, if I purchase a phone using AT&T Next (meaning it is on contract), can I still activate it using a Verizon SIM to unlock the phone and use it on my AT&T Next plan without problem. The reason anyone might want to do this is because the Verizon unlocked phone also works with pre-paid international SIM cards while traveling abroad. The question again - can you Verizon SIM activate an iPhone purchased from Best Buy on an AT&T Next plan and use it on AT&T without issue? Thanks!